Machine Bolts

Crossarm or machine bolts are used in the pole line industry. They have square heads and a semi-cone point and typically come with a square nut assembled. They are also typically hot-dip galvanized in order to protect the steel. We can manufacture crossarm bolts up to 1-1/2″ in diameter. Crossarm bolts follow the thread length guidelines used for pole line fasteners. More information about machine bolts is available on our educational microsite polelinefasteners.com.

Machine Bolt Dimensions

Click table to show drawing

Bolt Diameter

D

F

C

H

Body Diameter

Width Across Flats

Width Across Corners

Height

Max

Basic

Max

Min

Max

Min

Basic

Max

Min

1⁄2

0.515

3⁄4

0.750

0.725

1.061

0.995

21⁄64

0.348

0.308

5⁄8

0.642

15⁄16

0.938

0.906

1.326

1.244

27⁄64

0.444

0.400

3⁄4

0.768

11⁄8

1.125

1.088

1.591

1.494

1⁄2

0.524

0.476

7⁄8

0.895

15⁄16

1.312

1.269

1.856

1.742

19⁄32

0.620

0.568

1

1.022

11⁄2

1.500

1.450

2.121

1.991

21⁄32

0.684

0.628

11⁄8

1.149

111⁄16

1.688

1.631

2.386

2.239

3⁄4

0.780

0.720

11⁄4

1.277

17⁄8

1.875

1.812

2.652

2.489

27⁄32

0.876

0.812

13⁄8

1.404

21⁄16

2.062

1.994

2.917

2.738

29⁄32

0.940

0.872

11⁄2

1.531

21⁄4

2.250

2.175

3.182

2.986

1

1.036

0.964

13⁄4*

29⁄16

13⁄16

2*

215⁄16

15⁄16

Dimensions per ASME B18.2.1 1996

* ASME only defines head dimensions up to 1-1/2". Dimensions for 1-3/4 and 2" are approximate and not covered under the ASME dimensional specifications.

Take a quick tour of our shop and follow an order of 7/8″ diameter square head machine bolts through the manufacturing process. This video includes shearing, pointing, hot forging, roll threading, and galvanizing. Find out what it takes to make an order of large, custom machine bolts. Find more of our videos, or subscribe to us at pdxbolt on YouTube